Mon Frère Yves is a semi-autobiographical novel written by the French author Pierre Loti. It describes the friendship between French naval officer Pierre Loti and a hard-drinking Breton sailor Yves Kermadec during the 1870s and 80s. It was probably Loti's best-known book. The fictional Yves was, in reality, Loti's friend, the Breton sailor Pierre le Cor, whom he had sailed with on a number of voyages. A functional illiterate, le Cor was, however, tall, fair, and handsome; everything Loti wanted to be. Like Yves, le Cor was a heavy drinker, while Loti hardly drank at all. The two often spent time ashore either gambling, brawling, scheming childish pranks, or roaming the countryside of Brittany where le Cor introduced Loti to the lore of the Breton culture. In Brittany, Loti met le Cor's mother, and swore to watch over her son forever, although le Cor's hard-drinking often tested the bonds of their friendship.